Field of the Invention
The present invention relates to a wireless communication system and, more particularly, to a method and apparatus for transmitting and receiving audio streams in a wireless communication system supporting Bluetooth communication.
Discussion of the Related Art
Bluetooth is one of representative short-distance radio technologies in which various devices (e.g., a smart phone, a PC, an earphone, and a headphone) are interconnected and exchange information. Furthermore, Bluetooth is a technology applied to most of smart phones, PCs, and notebooks and is easily used by many people. The easy pairing procedure of Bluetooth stably provides connectivity between devices. A recent low energy (LE) technology consumes less power and can stably provide information of several hundreds of KB.
The core specification of a Bluetooth standard technology is divided into a basic rate/enhanced data rate (BR/EDR) and low energy (LE).
The Bluetooth low energy (hereinafter referred to as “BLE”) is a technology issued since Bluetooth Specification V4.0 and was designed for the purpose of high energy efficiency to existing Bluetooth.
The BLE technology may not be suitable for the real-time transmission of an audio stream in which a data transmission request is periodically generated because it has been designed so that a connection procedure is performed only when a data transmission request is generated between a master device and a slave device.
That is, when a slave requests data transmission and reception, a BLE master performs connection with the slave within a short time, exchanges required data with the slave within a relatively short time, and then performs disconnection.
In conventional Bluetooth communication, control and data transmission functions between a Bluetooth headset and a Bluetooth device (e.g., a smart phone) are provided using a hands free profile (HFP) for a telephone call (e.g., VoIP).
In conventional Bluetooth communication, from a viewpoint of an audio codec, a small number of codecs are mounted on a Bluetooth headset, and a smart phone performs a codec conversion so that audio stream data is transmitted and received between the Bluetooth headset and a remote terminal.
As described above, end to end audio stream delay and power consumption of a smart phone are increased due to a codec conversion in a smart phone.
In a Bluetooth device, a technology for call control, such as VoIP services (e.g., SIP, Skype, GoogleTalk, and FaceTime), through a smart phone or a PC is recently proposed.
In the case of the VoIP service, in general, an (audio) codec negotiation procedure between Bluetooth devices is performed prior to call connection between the Bluetooth devices.
Furthermore, in order to provide mutual compatibility between Bluetooth devices, a plurality of codecs must be mounted on and provided to a smart phone or a Bluetooth headset.
However, the application of a plurality of codecs to a Bluetooth headset is not preferred if limited resources (e.g., processing power and a memory unit) are taken into consideration. The application of a plurality of codecs to a smart phone inevitably increases the delay of the transmission and reception of end to end audio streams and power consumption of a Bluetooth device as described above.